The methyl and ethyl esters of the invention are all known as such. Ethyl 4,6,6-trimethyl-1,3-cyclohexadiene-1-carboxylate has been reported by I. Alkonyi et al. in Acta Chimica Academiae Scientiarium Hungaricae 1957, 12, 289 and is described as chemical intermediate. The methyl analogue has been similarly described by K.-F. Chen et al. in J. Chem. Soc. Perkin Trans. I, 1996, 1213. The methyl or ethyl esters of 4,6,6-trimethyl-3-cyclohexene-1-carboxylic acid have been disclosed as intermediate in J. Org. Chem., 1969, 34, 2196.
However, none of these documents discloses or suggests the organoleptic properties of the compounds of formula (I), or their use in the field of perfumery.
European patent application EP 955290 A1 discloses perfuming ingredients having a general formula that includes the compounds of the present invention. However, in that patent application, the compounds of the present invention are not specifically disclosed, do not belong to preferred class of compounds and there is no mention or suggestion of the particular and unique odor notes that can be conferred by the esters of the present invention.
Now, in perfumery, there is a recognized need for compounds capable of imparting odor notes of the type saffron and spicy so as to complete the needs of perfumers. The use of the compounds of formula (I) fulfils the above-mentioned need.